default(CancellationToken)是否等于CancellationToken.None?
看CancellationToken.None的实现，它只是返回default(CancellationToken).但是，我没有在CancellationToken的文档中看到两者是等效的.
Looking at the implementation of CancellationToken.None, it is simply returning default(CancellationToken). However, I see no reference in CancellationToken's documentation that the two are equivalent.
我想提供这样的API，但是直到我确定它会一直有效之前，我才提供:
I'd like to offer an API like this but not until I'm sure it'll always work:
Task DoSomething(CancellationToken token = default(CancellationToken))
default(CancellationToken)是否与CancellationToken.None相同是定义的行为，还是只是实现细节?
Is it defined behavior that default(CancellationToken) is the same as CancellationToken.None, or is this just an implementation detail?
在解决问题之后使用corefx，文档注释中有已更新，以使其成为有保证的功能:
After filing an issue with corefx, the documentation remarks have been updated to make this a guaranteed feature:
您还可以使用C#
default(CancellationToken)语句创建一个空的取消令牌.
You can also use the C#
default(CancellationToken)statement to create an empty cancellation token.